Also note that, as explained in more detail on the ticket[1], gadgetizing will be a bad idea. We might as well not remove it at all. A preference is a lot better than a gadget because (at least for now) its label will be localised a lot better, and more importantly: The option will show up in the relevant preferences section.
For reasons explained elsewhere, shipping gadgets by default with the Gadgets extension is not an option and generally counter-productive and bound to cause unwanted/unmaintained scripts to rot in wikis after being injected upon installation.
That's now how the Gadgets extension work, and imho it should stay that way.
Instead of gadgetization, a better option would be to move them into an extension (not the Gadgets extension). Which means the extension can: * add it to the preferences section where it used to be * use the same key as the old preference in core, so that users don't have to reset their preferences (as opposed to "gadget-foo").
Especially the latter is in my opinion a must-have for the smooth migration of any wiki that decides to install this "LegacyPreferences" extension after upgrading their MediaWiki-install.
Besides, most of the preferences discussed here aren't worth a gadget (I guess most communities will not want them in the preferences section after voting to have them disabled/removed from core). They don't add any significant features, only silly visual options that someone afraid of change insisted on in the past.
That is, of course, referring to preferences we would end up removing after some kind of consensus. I'm not talking about all preferences or any preference in particular .
In other words: If the story is "remove them from core, add as default-available[2] gadget". Then please, *please*, keep them in core. Because that wouldn't be an improvement over the current situation.
If we have good ground to remove them (because they're silly options that we don't want end-users to be thinking about), then we remove them. Don't move them from one junkyard to another.
-- Krinkle
[1] https://bugzilla.wikimedia.org/40346 [2] default-available != default-enabled